**Vishnu Suresh \* , Przemyslaw Janik , Jacek Rezmer and Zbigniew Leonowicz**

Faculty of Electrical Engineering, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland; przemyslaw.janik@pwr.edu.pl (P.J.); jacek.rezmer@pwr.edu.pl (J.R.); zbigniew.leonowicz@pwr.edu.pl (Z.L.) **\*** Correspondence: vishnu.suresh@pwr.edu.pl

Received: 25 December 2019; Accepted: 5 February 2020; Published: 7 February 2020

**Abstract:** The stochastic nature of renewable energy sources, especially solar PV output, has created uncertainties for the power sector. It threatens the stability of the power system and results in an inability to match power consumption and production. This paper presents a Convolutional Neural Network (CNN) approach consisting of different architectures, such as the regular CNN, multi-headed CNN, and CNN-LSTM (CNN-Long Short-Term Memory), which utilizes a sliding window data-level approach and other data pre-processing techniques to make accurate forecasts. The output of the solar panels is linked to input parameters such as irradiation, module temperature, ambient temperature, and windspeed. The benchmarking and accuracy metrics are calculated for 1 h, 1 day, and 1 week for the CNN based methods which are then compared with the results from the autoregressive moving average and multiple linear regression models in order to demonstrate its efficacy in making short-term and medium-term forecasts.

**Keywords:** convolutional neural networks; multi-headed CNN; CNN-LSTM; forecasting; solar output; sliding window; renewable energy
